How can I create a specific math expression on mathSE [duplicate]

Question

This meta-query discusses the following question:

Q1: How can I create a specific mathematical expression in a mathSE query?

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Edit Insert

Much of the information that a user would want is contained in the following links:

• https://math.stackexchange.com/help/notation
  In fact, this link provides an umbrella for the next link.

• MathJax basic tutorial and quick reference

However, I feel it is important to go beyond the information included in these links. I think that many new users are going to shy away from delving into the MathJax links, when all they want to know is how to format a specific symbol.

I expect a new mathSE user to opt for the path of least resistance. By providing the information in a consolidated manner to the new user, mathSE has:

• discouraged the new user from creating a mathSE query re MathJax, as has been done

• provided information re shortcuts that will be very attractive re the path of least resistance

• related to the previous point, these shortcuts could actually discourage new users from posting poorly formatted queries. Admittedly, this particular point is very iffy.

• contrasted MathJax against Latex to give the new user the opportunity to understand (somewhat) the website's formatting process

• provided definitive native Latex information re the Tex forum, the CTAN pdf, and simply googling.

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This query was inspired by a first query. Because my query focuses on the use of mathJax, I feel that it is more appropriate that this query be posted on meta-mathSE, rather than mathSE.

As in the first query, I am going to start the discussion with my own answer.

I favor the approach from the first query, which I am excerpting:

I will provide an answer below, but feel free to edit my answer or provide your own answer. Initially it will be a short list, but maybe it will grow over time. Please regard this question and its answers as a community resource.

Answer 1

For the broad question of how to format miscellaneous symbols or math expressions, you have the following resources:

1. https://math.stackexchange.com/help/notation.

2. mathSE has two different sandboxes that can each be explored to see how others have formatted a wide variety of (typically math) expressions:

   Sandbox for drafts of long, complex posts

   Formatting Sandbox

   If you see formatting that you like, you can pretend that you wish to edit the answer. Simply select edit and then copy the portion of the original formatting that you like.

   Then very carefully cancel the edit, so that the original answer is undisturbed.

3. Of course, this approach can also be taken on any mathSE query or answer that contains formatting syntax that you wish to copy. In fact, when providing an answer to someone else's query, you can consider the shortcut of pretending to edit the query that you are answering, copying part of the query's syntax, and pasting it directly into your answer.

4. Downloading the following pdf and then doing a search on the pertinent string:

   http://tug.ctan.org/info/symbols/comprehensive/symbols-a4.pdf

5. Exploring or posting a new query on https://tex.stackexchange.com/. This is where these questions are normally handled.

6. Google on the appropriate phrase. For example, to search for the latex syntax for the integral sign, you can google something like : latex integral.

7. I think that as a new user transitions to an intermediate knowledge of MathJax and Latex, it will become useful to understand the native Latex method and
   contrast it with the alterations needed for MathJax. Examples: the use of <br> for line breaks; the use of $\underline{\text{my underlined text}}$ for underlining; if the use of \; for spacing doesn't seem to be working correctly (perhaps in longer queries), substituting for it with ~.